Question

shape of carbanion is a) linear b) polar triangular c) pyramidal d) square planar

Answer 1

linear this is the answer

Answer 2

A carbanion is an anion in which carbon is trivalent (forms three bonds) and bears a formal negative charge in at least one significant mesomeric contributor (resonance form). Absent π delocalization, carbanions assume a trigonal pyramidal, bent, or linear geometry when the carbanionic carbon is bound to three (e.g., methyl anion), two (e.g., phenyl anion), or one (e.g., acetylide anion) substituents, respectively. 
hence option (c) is correct