Option (A) is correct. According to the textbook context, when the sun shines vertically over the Tropic of Capricorn in the southern hemisphere (around 22nd December), the weather is characterised by feeble high pressure conditions over the northern plain. The isobars of 1019 mb pass through northwest India, indicating high pressure. This occurs because it is winter in the northern hemisphere, resulting in low temperatures which cause high pressure to develop. Option (B) is incorrect as low pressure develops during summer (April-May) when the sun shines over the Tropic of Cancer, not Capricorn. Option (D) 'Loo' is also a summer phenomenon, not winter.