Which of the following statement (s) is/are true?

Options

A. A weak base B , has `K_(b) = 2.0 xx 10^(-5)` . The pH of any solution in which `[B^(-)] = [BH]` is 4.7
B. A buffer of acetic acid and potassium acetate in which `[CH_(3)COOH] = [CH_(3)COO^(-)] ` will have `pH = pK_(a)`
C. A mixture of `CH_(3)COOH and NH_(4)OH` acts as a buffer .
D. The pH of a solution made by mixing 1 M HCl and 1 M NaOH solution is 7