Answer: C
Step-by-step explanation:
A. Shows 3-Hexyne (NOT 2-HEXYNE)
B. Shows 7 carbons (too many) (NOT 2-HEXYNE)
C. Shows a triple bond (yne) and 6 carbons and it's on the second carbon (2-HEXYNE)
D. Shows two substitent on the second carbon but the triple bond is on the 3rd carbon so it's 2,2-dimethyl-3-heptyne (NOT 2-HEXYNE)