(B) $\dfrac{2}{13}$
There are 4 tens and 4 kings in a deck, giving 8 favourable outcomes.
$$P(\text{ten or king}) = \frac{8}{52} = \frac{2}{13}$$
Source: Chapter 14, Section 14.1
A standard deck has 13 cards per suit × 4 suits = 52 cards. There are exactly 4 tens and 4 kings (one of each suit), so 8 favourable outcomes in total. Simplify 8/52 by dividing by 4 to get 2/13. Option (D) shows 8/26 which is not fully simplified and is not a standard answer choice.