An unlit match is held near (not touching) a Bunsen flame. The match doesn't get hot enough to light because

a. the flame is not hot enough

b. air is a bad conductor of heat

c. the matchhead reflects radiation

d. the flame does not radiate any heat sideways

The answer is option D)

this is because the heat radiated by the flame is mostly absorbed by the air surrounding it, so the air becomes hot and its density decreases (because of expansion), therefore it goes up and it is replaced by cooler air. since all of the hot air flies up, non goes side ways to heat up the match stick, hence it remains cool and does not light up.

option A) also sounds correct, but it isn't. this is because the flame IS hot enough to burn the match stick, it's just that the match stick is positioned the wrong way