The correct answer is: A. less will be the secondary induced e.m.f.
The secondary induced e.m.f. is proportional to the rate of change of the magnetic flux linking the secondary winding. The leakage flux is the flux that does not link the secondary winding. Therefore, greater the secondary leakage flux, less will be the rate of change of the magnetic flux linking the secondary winding, and hence less will be the secondary induced e.m.f.
Option B is incorrect because the primary induced e.m.f. is proportional to the rate of change of the magnetic flux linking the primary winding. The leakage flux does not link the primary winding, so it does not affect the primary induced e.m.f.
Option C is incorrect because the primary terminal voltage is equal to the product of the primary induced e.m.f. and the turns ratio. The leakage flux does not affect the primary induced e.m.f., so it does not affect the primary terminal voltage.
Option D is incorrect because the leakage flux does affect the secondary induced e.m.f., as explained above.