Final answer:
Eastern Subterranean termites consume both summer and spring wood, relying on symbiotic microorganisms to digest lignin into utilizable carbohydrates.
Step-by-step explanation:
The termite that feeds on summer and spring wood is the Eastern Subterranean termite (C). Termites do not produce enzymes capable of breaking down lignin in wood. Instead, they rely on microorganisms in their digestive systems that produce an enzyme to degrade lignin into soluble carbohydrates, which the termites can use for nutrition.
Each species of termite has a different feeding preference and adaptation, and the Eastern Subterranean termite is known to consume both spring and summer wood, whereas others may prefer different types or conditions of wood.