Which of the following statements best describes the major difference between prophase I of meiosis and prophase of mitosis?
A. In prophase I, tetrads of homologous chromosomes form and crossing over occurs.
B. In prophase, the nuclear membrane dissolves and spindle fibers attach to the chromosomes.
C. In prophase I, the chromatin condenses to form visible chromosomes.
D. In prophase, the replicated chromosomes are linked together as sister chromatids.