What Is the Relationship Between Plants and Cyanobacteria

What is the relationship between plants and cyanobacteria?

A) Plants produce chlorophylls a and b and pass these pigments on to cyanobacteria.
B) Cyanobacteria use oxygen produced by plants and, in return, produce carbon dioxide for use in plants.
C) Some cyanobacteria form mutualistic relationships with plants, called lichens.
D) Cyanobacteria that were internalized and not broken down by plant cells formed chloroplasts.