Suppose three coins are tossed simultaneously. If $X$ denotes the number of heads,then the probability distribution of $X$ is:

• A

  $X=x$	$0$	$1$	$2$	$3$
  $P(X=x)$	$\frac{2}{8}$	$\frac{2}{8}$	$\frac{3}{8}$	$\frac{1}{8}$

• B

  $X=x$	$0$	$1$	$2$	$3$
  $P(X=x)$	$\frac{1}{8}$	$\frac{3}{8}$	$\frac{3}{8}$	$\frac{1}{8}$

• C

  $X=x$	$1$	$2$	$3$
  $P(X=x)$	$\frac{3}{8}$	$\frac{3}{8}$	$\frac{2}{8}$

• D

  $X=x$	$0$	$1$	$2$	$3$
  $P(X=x)$	$\frac{1}{8}$	$\frac{1}{8}$	$\frac{3}{8}$	$\frac{3}{8}$