FREE POINTS ALSO! Can you sub to my friend on YT she's an animator and she's trying to get to 1000 subs so plz help her out her name is ThatFanfictGirlZen!

Silverpoint is a. a technique using the blackish residue of impure carbon obtained by removing water from animal and vegetation substances. b. a technique involving the use of a metal point, and a thin silver wire, popular in the 14th and 15th centuries. c. a printmaking technique born from crayon manner that imitates the appearance of chalk lines. d. a technique used since the 16th century involving a stick filled with either colored or black graphite, a heated mixture of carbon and clay