If the statement Some trucks are polluting vehicles is given as true, which of the following statements could be immediately inferred to be false?

1.All trucks are polluting vehicles.

2.Some trucks are non-polluting vehicles.

3.Some trucks are not polluting vehicles.

4.No trucks are polluting vehicles.

A3 & 4 only

B2 & 3 only

C4 only ✓ Correct

D2, 3 & 4 only

Correct answer: (C) 4 only

Explanation

Only Statement 4 can be inferred false.

The given true proposition is the I form, some trucks are polluting vehicles.

The contradictory of an I proposition is the E form, no trucks are polluting vehicles.

When the I is true its contradictory E must be false, making Statement 4 false.

The remaining forms are left undetermined by a true I proposition.

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