Which of the following is true about trumpet mushrooms before cooking?

Trumpet mushrooms, also known as king oyster mushrooms, must be cleaned before cooking. This is essential because they often have dirt and debris clinging to their surfaces, as they grow in soil. Properly cleaning them ensures that any soil residue is removed, allowing for a better taste and texture in the final dish. Before cooking, it's common practice to gently wipe the mushrooms with a damp cloth or rinse them under cold water and dry them thoroughly, especially since they can absorb water during the rinsing process.

The other statements do not convey accurate information about trumpet mushrooms. For instance, while they can be prepared in various ways, they shouldn't be limited strictly to raw consumption or reserved only for drying, as these mushrooms exhibit best flavor and texture when cooked.