A box has 13 distinct pairs of socks. Let $p _ { r }$ denote the probability of having at least one matching pair among a bunch of $r$ socks drawn at random from the box. If $r _ { 0 }$ is the maximum possible value of $r$ such that $p _ { r } < 1$, then the value of $p _ { r _ { 0 } }$ is (A) $1 - \frac { 12 } { { } ^ { 26 } C _ { 12 } }$. (B) $1 - \frac { 13 } { { } ^ { 26 } C _ { 13 } }$. (C) $1 - \frac { 2 ^ { 13 } } { { } ^ { 26 } C _ { 13 } }$. (D) $1 - \frac { 2 ^ { 12 } } { { } ^ { 26 } C _ { 12 } }$.
A box has 13 distinct pairs of socks. Let $p _ { r }$ denote the probability of having at least one matching pair among a bunch of $r$ socks drawn at random from the box. If $r _ { 0 }$ is the maximum possible value of $r$ such that $p _ { r } < 1$, then the value of $p _ { r _ { 0 } }$ is\\
(A) $1 - \frac { 12 } { { } ^ { 26 } C _ { 12 } }$.\\
(B) $1 - \frac { 13 } { { } ^ { 26 } C _ { 13 } }$.\\
(C) $1 - \frac { 2 ^ { 13 } } { { } ^ { 26 } C _ { 13 } }$.\\
(D) $1 - \frac { 2 ^ { 12 } } { { } ^ { 26 } C _ { 12 } }$.