Thermodynamics problem

[xyz]

Hi,there
I got a question from my sample test. That is:

"After passing 2B with flying colors, you are called one winter to rescue a physics 10 student who unknowingly puts his tongue against a cold steel post. As you peel his tongue off the post, you knowingly explain that, next time, he should instead lick a wooden post because:
a)steel has a higher specific heat than wood
b)wood is not as good a radiator of heat
c)steel has a higher specific gracity
d)steel is a better heat conductor
e)wood is not magnetic

I guess the key to the question is D. If I am right, why? If not, why?

 

[Claude Bile]

D is correct.

Metal is much better at conducting heat. Therefore if someone puts their tongue against cold metal, the metal will efficiently conduct heat away from tongue.

In wood it is different. Wood has low thermal conductivity, which means that the heat from the tongue will remain localised around the contact area, which would prevent any tongues getting stuck to it.