Answer:
The correct option is 3, i.e., Distributive property.
Step-by-step explanation:
Distributive property: If a, b and c are real three numbers, then

The given expression is

Using distributive property in can be rewritten as


It means distributive property allows as to write the expression (5 – 2i) – (1 + 8i) as 5 – 2i – 1 – 8i.
Therefore, the correct option is 3.