Bob: " Hi, Stanley. What is the coefficient of the variable in this algebraic expression $3x^{2}-4$?"  Stanley:" I can give you a hint. The value of the coefficient is $7$ more than the constant."  Stanley\textquotesingle s hint is~\uline{~~~~~~~~~~}~and the coefficient of the variable is~\uline{~~~~~~~~~~}~. 
选项为:A:correct, $3$  B:correct, $-4$  C:incorrect, $3$  D:incorrect, $4$  请回答其中一个选项.