Q.6

The horse has played a little known but very important role in the field of medicine.
Horses were injected with toxins of diseases until their blood built up immunities.
Then a serum was made from their blood.
Serums to fight with diphtheria and tetanus were developed this way.

It can be inferred from the passage, that horses were

Options:

(A) given immunity to diseases

(B) generally quite immune to diseases

(C) given medicines to fight toxins

(D) given diphtheria and tetanus serums

Reading inference questions in exams like GATE and GRE require drawing logical conclusions from short passages, testing comprehension beyond stated facts. This passage describes horses injected with disease toxins to produce immunities in their blood, from which serums for diphtheria and tetanus were made.

The correct answer is (A) given immunity to diseases, as the process actively built immunities in the horses through toxin exposure.

Why (A) is the Best Inference

The passage states horses were “injected with toxins… until their blood built up immunities,” directly implying they were given (induced) immunity as a result of the procedure. This mirrors antibody production in biotech, where antigens stimulate immune responses for serum harvesting.

Explanation of All Options

Each option tests if you stick to the text or add assumptions:

• (A) Given immunity to diseases
  Accurate inference. Injections led to immunity buildup, making horses immune post-treatment.

• (B) Generally quite immune to diseases
  Incorrect. Passage doesn’t claim natural or pre-existing immunity; it describes an induced process.

• (C) Given medicines to fight toxins
  Wrong. No medicines mentioned—only toxin injections to trigger natural immunity.

• (D) Given diphtheria and tetanus serums
  Illogical. Horses produced the serums from their blood; they weren’t recipients.

Quick Comparison Table

This technique relates to monoclonal antibody production in modern biotech. Practice by inferring unstated outcomes from lab protocols.