Concept:The rain-bearing monsoon winds blow from the Atlantic Ocean. They start as the south-east trade winds of the Southern Hemisphere and turn to blow from the south-west after crossing the Equator, so they reach Ghana as the (south-west) monsoon.
Solution:These moist winds blow over southern Ghana mainly from about April to October, giving the rainy season (the south has two rainfall peaks within this period, around June and October).
From about November/December to March the dry north-east trade winds (harmattan) blow from the Sahara, so those months are mostly dry.
Key point: The winds that bring rain to Ghana are often called the south-west monsoon; they are the south-east trades deflected after crossing the Equator.
Answer:Option D (April and October)