योग्य जोडया लावा :
यादी I (वृष्टीचे प्रकार) — यादी II (आवश्यक स्थिती)
अ. अभिसरण पर्जन्य — I. कमीदाबाशी संबंध असतो
ब. प्रतिरोध पर्जन्य — II. हवेचे तापमान वाढल्याने
क. आवर्त पर्जन्य — III. समुद्रावरुन येणारा उबदार हवेचाझोत हिवाळयात थंड जमीनीवरुन जातो
ड. सीमावर्ती पर्जन्य — IV. बाष्पसंयुक्त हवेस डोंगर उतारावरुन वर सरकावेच लागते

The correct answer is Option D (a-IV, b-II, c-I, d-III).

Key Points:
• Rainfall Mechanisms and Conditions:
• a. Convectional Rain (अभिसरण पर्जन्य): Occurs when intense solar heating of ground expands air, causing warm buoyant air to rise vertically, condense, and precipitate (4 o'clock rain).
• b. Orographic Rain (प्रतिरोध पर्जन्य): Occurs when moisture-laden winds encounter high mountain barriers and are forced to ascend up slopes, cooling adiabatically.
• c. Cyclonic Rain (आवर्त पर्जन्य): Caused by low-pressure cyclonic depressions where winds converge inwards and ascend rapidly.
• d. Frontal / Border Rain (सीमावर्ती पर्जन्य): Happens when warm, moist oceanic air masses pass over cold continental air/land surfaces in winter.
• As per the official MPSC Final Answer Key for 2012 GS-1 (Set A), the designated correct option is Option (4).
• Key Takeaway: Convectional (thermal uplift), Orographic (mountain barrier), Cyclonic (low-pressure convergence), and Frontal (air-mass boundary) represent the four primary mechanisms of precipitation.