$$ Total\ students=25 $$

$$ Median\ score=80 $$

No 2 students got the same test score.

The median for an odd number of terms is

$$ Median=(\frac{n+1}{2})^{th} $$

The median of 25 terms is

$$ Median=(\frac{25+1}{2})^{th}=13^{th}\ term $$

As students got distinct scores so all the 25-13=12 students above 13th got scores greater than 80. Therefore, choice B is correct.