Suppose We Have the Following Definition

Suppose we have the following definition:
Vector<int> vec, vec1;
//use push_back to put 10 values into vec
Vector<int>::iterator p = vec.begin) ;
Vector<int>::const_iterator q = vec.begin) ;
Which of the following expressions is not legal? Treat the effect of these as non-cumulative.

A) *p = 1;
B) *q = 1;
C) p = vec.end ) ;
D) q = vec1.end) ;