Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Which of the following statements most accurately defines the market portfolio in capital market theory? The market portfolio consists of all:
Option A:risky assets.
Option B:tradable assets.
Option C:investable assets.

Answer: A