How does the old man know immediately the size of the great marlin he has caught?

A、Soonaftertakingthebait,thefishjumpsintotheair,showingitselftotheoldman.
B、Santiagohasencounteredthisfishbeforeasayoungerman.
C、Hepullsandpullsonthelineandnothinghappens.
D、Hedoesn’tknowthesizeofthefishuntilafterthesharkshaveattackedit.