Step One
Find <BEC
<BEC = 2x + 3 x = 30
<BEC = 2*30+3
<BEC = 60 + 3
<BEC = 63
Step Two
Find AED
<AED = <BEC Why? because the 2 angles are vertically opposite. Vertically opposite angles are equal.
Step Three
Now you have to find which given expression equals 63. Remember that the value of x has not changed. x = 30.
A is wrong 4x = 4*30 = 120. That is far too large.
B 3x - 27 looks good because the answer will end in a 3. 3*30 - 27 = 90 - 27 = 63. The answer is B.
C is wrong because 5x = 5*30 = 150. It's already too big.
D is wrong because 30 + 43 = 73. This is your second best answer, but it is still incorrect.