C Programming Quizzes C Language Arrays And Strings

Question:
Let x be an array. Which of the following operations are illegal?
I.   ++x
II.  x+1
III. x++
IV.  x*2

Option A):
I, III and IV
Option B):
I and II
Option C):
II and III
Option D):
I, II and III

Correct Answer is Option A):
I, III and IV