Find the Missing Monomial, Factor or Term $$7 x ^ { 5 } \cdot ? = 28 x ^ { 7 }$$

Multiple Choice

Find the missing monomial, factor or term.
- $$7 x ^ { 5 } \cdot ? = 28 x ^ { 7 }$$

A) $4 x ^ { 2 }$
B) $- 4 x ^ { 2 }$
C) $- x ^ { 2 }$
D) $x ^ { 2 }$