单项选择题

There is an 80 percent chance of rain on each of the next six days. What is the probability that it will rain on exactly two of those days

A．<TABLE border=0 cellSpacing=0 cellPadding=0 width="90%"><TBODY><TR><TD vAlign=top>A. 0.15364. </TD></TR></TBODY></TABLE>
B．<TABLE border=0 cellSpacing=0 cellPadding=0 width="90%"><TBODY><TR><TD vAlign=top>B. 0.24327. </TD></TR></TBODY></TABLE>
C．<TABLE border=0 cellSpacing=0 cellPadding=0 width="90%"><TBODY><TR><TD vAlign=top>C. 0.01536.</TD></TR></TBODY></TABLE>