Which statement correctly differentiates a simile from a metaphor?

Which statement correctly differentiates a simile from a metaphor?

• A. A simile uses direct equivalence; a metaphor uses like or as.
• B. A simile uses imagery exclusively; a metaphor uses symbolism.
• C. A simile uses capitalization; a metaphor uses punctuation.
• D. A simile uses like or as to compare; a metaphor asserts a direct equivalence.

Answer: (D)