Some Slow-Growing Trees Have Leaves That Are High in Lignin

Some slow-growing trees have leaves that are high in lignin. The most likely advantage of lignin to such trees is that lignin

A) has a low C:N ratio, and thus it enriches the soil in its immediate vicinity.
B) kills certain microorganisms that are needed for plants with high growth rates, protecting the trees from competitive exclusion.
C) has high concentrations of phosphorus, which is necessary for slow-growing trees.
D) slows the rate of decomposition, thereby lowering the fertility of the soil and allowing the trees to outcompete plants with high growth rates.