(3 + 8i)(-2 - i)

What letter represents an imaginary number?

3+√-4

2 - √-9

 $3+3i+8-2i-7$  

 $-3+6i-\left(-5-3i\right)-8i$  

 $4i\left(-2-8i\right)$  

 $5i\cdot i\cdot-2i$  

 $\left(2-4i\right)\left(-6+4i\right)$  

 $\left(1-7i\right)^2$