Question

which set of processes must occur to form soil?
weathering breaks rocks into minerals and plants die and decay
erosion transports mineral particles and plants die and decay
erosion and weathering
plants produce loam and plants produce humus

Explanation:

Soil formation involves weathering which breaks rocks into minerals and the decay of plants. Erosion mainly moves materials and plants don't directly produce loam in the key - sense of soil formation. Weathering and plant decay are fundamental.

Answer:

weathering breaks rocks into minerals and plants die and decay