Choose the most appropriate word from the options given below to complete the following sentence:
Under ethical guidelines recently adopted by the India Medical Association, human genes are to be manipulated only to correct diseases for which ________ treatments are unsatisfactory.
A. similar B. most C. uncommon D. available
GATE 2011 · General Aptitude · Most Appropriate Word · medium
Answer: D. available
Understand the conditional structure: The sentence says gene manipulation is allowed only to correct diseases where [type of] treatments are unsatisfactory. The blank must describe treatments that exist but fail — pointing to currently available treatments.
Test each option: A. similar — 'similar treatments' is vague and illogical here. B. most — 'most treatments are unsatisfactory' overstates the problem. C. uncommon — 'uncommon treatments' are not the threshold reference. D. available — 'available treatments are unsatisfactory' correctly means existing treatments do not work. Answer: D.