For which of the following sets is the given $p$ an accumulation point?

A. $S =$ the rational numbers in $[0,1]$ and $p = .5$

B. $(1, 6)$ and $p = 6.1$

C. $S = \mathbb{Q}$ and $p = \pi$

D. $S =$ the irrational numbers in $[0,1]$ and $p = .5$

E. None of the above