Please answer right away and don’t guess

Answer: Third Option
[tex]P (M\ or\ N) = 0.8[/tex]
Step-by-step explanation:
In this case, we have two non-disjoint events.
So the probability of M or N occurring is
[tex]P (M\ or\ N) = P(M) + P(N) - P (M\ and\ N)[/tex]
We know that in this problem
[tex]P(M) = 0.7\\\\P(N) = 0.5[/tex]
[tex]P(M\ and\ N) = 0.4[/tex]
So
[tex]P (M\ or\ N) = 0.7 + 0.5 - 0.4[/tex]
[tex]P (M\ or\ N) = 0.8[/tex]
The answer is the third option