Answer:
B
Step-by-step explanation:
Using the rule of radicals
[tex]\sqrt{a}[/tex] × [tex]\sqrt{b}[/tex] ⇔ [tex]\sqrt{ab}[/tex] and
[tex]\sqrt{-1}[/tex] = i
Given
[tex]\sqrt{-80}[/tex]
= [tex]\sqrt{16(5)(-1)}[/tex]
= [tex]\sqrt{16}[/tex] × [tex]\sqrt{5}[/tex] × [tex]\sqrt{-1}[/tex]
= 4 × [tex]\sqrt{5}[/tex] × i
= 4i[tex]\sqrt{5}[/tex] → B
