Which process, in order, would be necessary for this sequence of the rock cycle: rock → metamorphic rock → igneous rock

Heat and pressure → melting → cooling

Weathering and erosion → compaction → weathering and erosion

Melting → cooling → melting → erosion

Cooling → melting → cooling → weathering and erosion

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?