单项选择题
Which of the following statements about follicular lymphoma is incorrect ()
A、Follicular lymphoma is a type of lymphoma that originates from follicular center B cells (centroblasts or centroblasts), morphologically at least part of the follicles are present
B、Morphologically, the lymph nodes have partially retained filtration
C、According to the WHO classification of lymphoma, follicular lymphoma can be further divided into grades 1-4
D、According to the proportion of tumor follicles and diffuse infiltration, it is divided into: follicular (follicular > 75 %), follicular diffuse (25% to 75% of follicles), diffuse (follicular <25%)