During metaphase the spindle fiber form a lemon shaped array called the

Mitotic spindle

Explanation:

During prophase, the formation of the spindle begins. The mitotic apparatus at metaphase consists of two parts: lemon-shaped mitotic spindle and a pair of asters. Mitotic spindle consists of microtubules. There are three different types of microtubules: astral microtubules, kinetochore microtubules, and polar microtubules. The astral microtubules form the asters and radiate out from centrosome.

The kinetochore microtubules are attached to the chromosomes via kinetochores. Polar microtubules are not attached to the chromosomes. The polar microtubules from opposite poles overlap. Altogether, the mitotic spindle serves to align the chromosomes at the cell's equator to facilitate the movement of sister chromatids to opposite poles during anaphase.

the answer to your question is b