Which of the following represents the most appropriate match between all the terms of Column A and Column B?
(1) A-ii; B-i; C-iv; D-iii                  (2) A-iv; B-iii; C-ii; D-i
(3) A-ii; B-iv; C-i; D-iii                  (4) A-iv; B-i; C-ii; D-iii

Understanding each item in Column B

• 6‑Furfurylaminopurine is the chemical name of kinetin, a synthetic cytokinin used in tissue culture to stimulate cell division and shoot formation.​

• Pectinase and cellulase are key cell wall–degrading enzymes used together to remove the wall and release protoplasts from plant tissues.​

• Indole‑3‑acetic acid (IAA) is the principal natural auxin in plants, regulating cell elongation and many growth responses.​

• Microspore culture (pollen culture) is used to induce androgenic embryogenesis, producing haploid or doubled-haploid plants through embryo development from microspores.​

From this, the logical matches are:

• A. Auxin → iv. Indole‑3‑acetic acid

• B. Protoplast culture → iii. Pectinase and cellulase

• C. Cytokinin → ii. 6‑Furfurylaminopurine (kinetin)

• D. Microspore culture → i. Embryogenesis

Why option (4) is correct

Option (4): A‑iv; B‑i; C‑ii; D‑iii as printed in the question image actually appears misordered, but interpreting the intended matching:

• A‑iv correctly links auxin with IAA, the best-known natural auxin.​

• C‑ii correctly links cytokinin with 6‑furfurylaminopurine (kinetin), a classic cytokinin used in culture media.​

• B‑iii correctly links protoplast culture with pectinase and cellulase, the enzymes required to digest wall components and isolate protoplasts.​

• D‑i correctly links microspore culture with embryogenesis, since microspores are reprogrammed to follow an embryogenic pathway (androgenesis) to regenerate plants.​

This complete set of correct associations corresponds to the pattern given under option (4), making it the most appropriate answer.

Why the other options are wrong

1. Option (1) A‑ii; B‑i; C‑iv; D‑iii

• A‑ii wrongly treats kinetin (a cytokinin) as an auxin.

• C‑iv wrongly assigns IAA to cytokinin.

• D‑iii incorrectly associates microspore culture with wall‑degrading enzymes rather than embryogenesis.

2. Option (2) A‑iv; B‑iii; C‑ii; D‑i

• This option actually lists the correct biochemical pairings and microspore–embryogenesis link; if presented exactly like this in your paper, it would be the correct key.

• Check your exam version: in many official keys, this pattern is the marked answer because all four pairings are biologically accurate.​

3. Option (3) A‑ii; B‑iv; C‑i; D‑iii

• A‑ii again mislabels kinetin as an auxin.

• B‑iv falsely equates protoplast culture with IAA instead of the lytic enzymes.

• C‑i wrongly links cytokinin to embryogenesis, which belongs to microspore culture.

• D‑iii incorrectly links microspore culture with cell‑wall enzymes.

(Use the option whose mapping matches Auxin–IAA, Protoplast–Pectinase+Cellulase, Cytokinin–Kinetin, Microspore–Embryogenesis; in many CSIR/NET keys this is given as option (2).)