For Valine (K_a1 = 5

For valine (K_a1 = 5.2 × 10−³ and K_a2 = 1.9 × 10−¹⁰) ,what is the pH at the isoelectric point?

A) 2.28
B) 6.00
C) 7.00
D) 8.00
E) 9.72