What (35) __________ someone to become a lefthand?

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of primary stress in each of the following questions.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 34 to 38.

      Left-handers are the odd ones out. Sure, lefties (34) __________ up about 10 percent of the population - but, frankly, it seems like society has forgotten about them. Just consider all of the right-handed gadgets, awkwardly designed desks, and cooking tools that fit comfortably only in your right hand. What (35) __________ someone to become a lefthand? Scientists aren’t exactly sure, but research points to a complex makes between genes and environment. While no exact set of “leftie genes” have been discovered, people who dominantly use their left hands do have (36) __________ left-handed family members. And researchers have found different brain wirings in righties vs. lefties. But no matter (37) ______ it is that drives someone to use their antipodal paw, science has also uncovered a particular set of personality traits that left-handed people tend to have. (38) __________  for all of you lefties, leftie-loving righties, and ambidextrous folks out there – it’s time to brush up on your left-handed knowledge and help put an end to leftie discrimination once and for all.

(Adapted from FCE Use of English)