Must or Could be True GMAT, GRE Question

If 4<(7-x)/3, which of the following must be true?

I. 5<x
II. |x+3|>2
III. -(x+5) is positive

A) II only
B) III only
C) I and II only
D) II and III only
E) I, II and III

One way to try these is by plugging in numbers.

Given that x<−5x<−5, we could pick a number that satisfies this condition, lets say x=−7

I. 5<x, so ask is 5<−7? 

Not true: Cross Off

II. |x+3|>2, plug in -7 in place of x, we get |−7+3|>2

|4|>2 

True: Keep

III. −(x+5)>0,−(−7+5)=−(−2)=2>0−(x+5)>0

True: Keep

II & III only

D.