The answer is
Recombination is an exchange between homologous chromosomes (e.g. chr 1 from mom x chr 1 from dad). Since it usually happens during meiosis, these strands are later separated. Recombination can be unequal or equal, but it's usually equal, and unequal crossovers are generally quite small (but a common source of addition/deletion).
Reciprocal translocation refers to an exchange between different chromosomes (e.g. chr 1 x chr 2). It is considered a large scale mutation (resulting in a large addition to one chromosome, and a large deletion in another).
The correct option would be c.
Competition because they are fighting over a limited resource.
Enzymes are important for allowing and speeding up reactions in an organism. They do this by orienting chemical compounds and or substances so that they can easily break and form new products easily, the activation energy is lowered upon the use of such enzymes.