Which of the Following Is an Important Role for Fungi

Which of the following is an important role for fungi in the carbon cycle?

A) Fungi help release fixed carbon back to the environment for other plants and photosynthetic organisms to utilize.
B) One of fungi's main roles is to provide already fixed carbon to plants that the plants then use for the production of cellular tissues.
C) Fungi get involved in the fixation of carbon by undergoing photosynthesis.
D) Fungi reduce atmospheric carbon dioxide.