Which of the following choices adds a comment that says "currency format" to the end of the line of code?

Question $26$ options:

a$)$

string amount $=$ total.ToString$("$c$")$; $--$ currency format

b$)$

string amount $=$ total.ToString$("$c$")$; # currency format

c$)$

string amount $=$ total.ToString$("$c$")$; $\text{'}$ currency format

d$)$

string amount $=$ total.ToString$("$c$")$; $//$ currency format