Which of the following disjunctions is false ?A. 4 - 3 = 2 or 6 · 3 = 9B. 5 · 6 = 30 or 3 + 4 = 7C. 8 + 3 = 11 or 5 · 4 = 23D. 7 + 6 = 13 or 5 · 2 = 10

A disjunction is false if both parts of the disjunction are false; otherwise, it is true
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Choice A

4-3=2 is false
6*3=9 is false

both parts are false, so overall the entire disjunction is false
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Choice B

5*6=30 is true
3+4=7 is true

Neither part is false, so overall the entire thing is true
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Choice C

8+3=11 is true
5*4=23 is false

While second piece is false, the overall disjunction is true. The first part (true) makes the whole thing true.
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Choice D

7+6=13 is true
5*2=10 is true

Neither part is false, so overall the entire thing is true
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In summary, we have

A. False
B. True
C. True
D. True

Making choice A the only answer that is false. So choice A is the final answer