Choose the sentence that is closest in meaning to the given one

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Choose the sentence that is closest in meaning to the given one
1.     At the moment, Mr. Lam is buying a map because he isn’t sure which way to take.
a.      If Mr. Lam is not sure which way to take, he will buy a map.

b.     If Mr. Lam bought a map, he wouldn’t be sure which way to take.

c.      If Mr. Lam were sure which way to take, he wouldn’t stop to buy a map.

d.     If Mr. Lam is sure which way to take, he wouldn’t stop to buy a map.