He writes ___ ink.

A. WITH
B. IN
C. FOR
D. ON

When we use ( pen) to write, we use ( ink) instead of (pen). Then we have to use the preposition ( in ) but not ( with). Eg. I write in ink.

When we use pencil, we have to use ( with) but not ( in). Eg. I wrote with a pencil.

I write in ink. Or I write with a pencil.