A C programmer should not use an expression like the one that follows because ______.

n = i + x * ++i;

a. the expression may produce different results on different ANSI C compilers
b. it is illegal to have two consecutive operators
c. the ++ operator cannot be used in combination with other arithmetic operators
d. the increment operator cannot be used in the same expression as the addition operator
e. none of the above

a. the expression may produce different results on different ANSI C compilers