A wave is described by the equation$$y$=8$sin$[2$$($x$20+$t$2]$y$=8$sin$[2$$($x$20+$t$2]$ where all distances are measured in centimeters and the time is measured in seconds. Which of the following is correct?

Select one:

a$.$

The amplitude is $4$ cm$.$

b$.$

The wavelength is$(10/$$)(10/$$)$ cm$.$

c$.$

The velocity$($v$)($v$)$ is $10$ cm$/$s$.$

d$.$

The frequency is $2$ Hz$.$