Solution:The correct matching is A-4, B-3, C-1 and D-2.Cirrus is a high cloud made of ice crystals. These clouds. typically appear delicate and wispy with white strands. They are usually formed when warm, dry air rises, causing water vapour deposition onto rocky or metallic dust particles at high altitudes.
Cumulus humilis are clouds with vertical extent, common in the summers, that are often referred to as 'fair weather cumulus'. If they develop into cumulus mediocris or cumulus congestus, thunderstorms could form later in the day.
Nimbostratus clouds are dark, grey featureless layers of clouds, thick enough to block the sun. These clouds are often associated with frontal systems provided by mid-latitude cyclones.
Stratus clouds are low level clouds characterised by horizontal layering with a uniform base, as opposed to convective or cumuli-form clouds that are formed by rising thermals. These clouds are essentially above ground fog formed either through the lifting of morning fog or through cold air moving at low altitudes over a region.