What are the bipolar spindle fibers made of?

Match the following and select the correct option:
$List-I$ (Phase) | $List-II$ (Event)
$(A)$ Prophase | $(i)$ Centromere attaches to spindle fibers
$(B)$ Metaphase | $(ii)$ Spindle fibers disappear
$(C)$ Anaphase | $(iii)$ Formation of spindle fibers
$(D)$ Telophase | $(iv)$ Spindle fibers shorten

How do the chromosomes appear in the given figure?

What is the definition of the mitotic index?

Which phase begins with the condensation of chromosomes along their longitudinal axis?

In mitosis,the spindle fibers are ........