We can divide the task (S) into 2 sub-task.
S1- Choosing a team of 11 from 15 players
S2- Now selecting a caption from that team.
After that required no. of ways can be obtained by applying product rule.
S= S1.S2
Choosing a team of 11 from 15 players can be done in $\binom{15}{11}$ ways.
Now selecting a caption from that team of 11 players can be done in 11 ways.
So total no, of ways= 11.$\binom{15}{11}$
So B is the correct option.