Add or Subtract and Simplify $(3+9 \mathrm{i})-(-7+\mathrm{i})$ A) $10+8 \mathrm{i}$ B) $10-8 \mathrm{i}$

Multiple Choice

Add or subtract and simplify.
- $(3+9 \mathrm{i}) -(-7+\mathrm{i})$

A) $10+8 \mathrm{i}$
B) $10-8 \mathrm{i}$
C) $-10-8 \mathrm{i}$
D) $-4+10 \mathrm{i}$