“go ahead regardless of where or whom you hit.”  the president was instructing the investigation team to:  

This is part of a saying by United States' president James Garfield:

"Go ahead regardless of where or whom you hit. I direct you not only to probe this ulcer to the bottom, but to cut it out."

The president was instructing the investigation team to investigate all involved people, regardless their political parties.

In spanish:

Esto es parte de una frase del presidente de los Estados Unidos, James Garfield:

"Adelante, independientemente de dónde o a quién golpees. Te ordeno no solo que investigues esta úlcera hasta el fondo, sino también que la cortes".

El presidente estaba ordenando al equipo de investigación que investigara a todas las personas involucradas, independientemente de sus partidos políticos.

the correct answer is c