The correct answer is A. Rightward.
A dry weather will decrease the supply of wheat. This is because farmers will be able to produce less wheat due to the poor growing conditions. As a result, the supply curve for wheat will shift to the right, indicating that more wheat will be supplied at each price.
Option B is incorrect because a dry weather will decrease the supply of wheat, not increase it.
Option C is incorrect because a dry weather will not affect the demand for wheat, only the supply.
Option D is incorrect because a dry weather will cause the supply curve for wheat to shift to the right, not remain constant.