The correct option is A 6 terms
A polynomial of degree 5 is
a0x5+a1x4+a2x3+a3x2+a4x+a5, where a0,a1,a2,a3,a4, a5 are real constant.
Clearly maximum term in this polynomial are 6 and also minimum term can be one a0x5.
Therefore, a polynomial of degree 5 in x has at most 6 terms.