Step 1: Luteoma of pregnancy is a non-neoplastic, tumour-like enlargement of the ovary that develops during pregnancy in response to high levels of human chorionic gonadotropin.
Step 2: It typically appears as bilateral, multinodular, solid ovarian masses, so the statement that it is usually bilateral is correct.
Step 3: Histologically, normal ovarian tissue is replaced by a solid proliferation of luteinized stromal cells, so the option about luteinized cells is also correct.
Step 4: It is a benign, self-limiting condition that regresses spontaneously after delivery and needs no treatment. Since all three statements are true, the answer is all of the above.