The correct option is (ii) and (iv).

Recombination refers to the process by which pieces of DNA are broken and combined to produce new combinations of alleles, resulting in offspring with combinations of traits that differ from those found in either parent. The mechanisms responsible for generating these recombinant genotypes in future generations during sexual reproduction are:

1. Crossing over of bivalents (iv):
During Prophase I of meiosis I, homologous chromosomes pair up to form structures called bivalents (or tetrads). The non-sister chromatids of these homologous chromosomes undergo physical exchange of genetic segments at points called chiasmata. This process, known as crossing over, directly reshuffles paternal and maternal alleles along the chromosomes, creating unique recombinant chromatids.

2. Independent assortment during meiosis I (ii):
During Metaphase I and Anaphase I of meiosis I, homologous chromosome pairs align randomly at the cell equator and then separate. The orientation and separation of one pair of chromosomes do not affect any other pair. This independent assortment ensures a random distribution of maternal and paternal chromosomes into the resulting gametes, leading to novel chromosome combinations (recombination) in the next generation.

Why other options are incorrect:
• Mutation (i): While mutations introduce entirely new alleles by changing the DNA sequence, they are distinct from the process of recombination, which reshuffles existing alleles.
• Independent assortment during meiosis II (iii): Meiosis II involves the separation of sister chromatids rather than the independent assortment of homologous chromosome pairs (which only happens in meiosis I). Therefore, it is not considered a primary mechanism for independent assortment leading to recombination.