If the strMsg variable contains the string Her birthday is Friday!, which of the following assigns the

Question:

If the strMsg variable contains the string “Her birthday is Friday!”, which of the following assigns the number 16 to the intNum variable?
a. intNum = strMsg.Substring(0, "F")
b. intNum = strMsg.Contains("F")
c. intNum = strMsg.IndexOf("F")
d. intNum = strMsg.IndexOf(0, "F")