If x,y,z>0, and

a)1

b)2

c)3

d)4

I am new to logarithm. I know only the basics. Can anyone tell me from where I can learn logarithm in detail. Thanks in advance.

This question is from the sample paper of my entrance exam I need to learn algorithm to this level so that I can get clear. :)

I hope someone can help :). Thanks once more time in advance.