What Does a Cocoon Nebula Do to Deserve Its Name

What does a cocoon nebula do to deserve its name?

A) Its gravity prevents the evolving protostar from expanding rapidly and dissipating as a consequence of its very high temperature.
B) It enhances the visibility of a faint protostar by scattering the light from it, much as a mist spreads and enlarges the light from street lamps.
C) It hides protostars by absorbing the very large amounts of visible light emitted by them but reemits this energy as infrared radiation.
D) It absorbs all the electromagnetic radiation from protostars, rendering them invisible until they have melted and evaporated the dust and ionized the gas in the nebula.