The steepness of a line is determined by its slope m.

If you have learned 

y = mx + b, and that m, the coefficient of x is the slope. 

then you know that the slope of

y = 2x + 5 is 2 because the coefficient of x is 2.

You should know that the slope of answer A

y = x + 5 is 1 because the coefficient of x is 1. So it's not as steep. 

You should know that the slope of answer B

y = 4x + 5 is 4 because the coefficient of x is 4. So it's steeper.

You should know that the slope of answer C

y = 2x + 8 is 2 because the coefficient of x is 4. So it's the SAME
steepness, it's not steeper.

You should know that the slope of answer D

y = -2x + 5 is -2 because the coefficient of x is 4. So it's the SAME
steepness, it's not steeper.  The negative sign just means that it 
slopes down to the right.

Lines with positive slopes slope up to the right like this / and lines 
with negative slopes slope down to the right like this \.

Anyway, the correct answer is B, for it's the only one steeper than
the given line with slope 2.

Edwin