Which of these is true of meiosis?
a. > n
b. > 2n
c. > 2n
d. > n

2n --> n 

You start with a cell with a diploid set of chromosomes (2n). In S phase (a part of interphase), the chromosomes are doubled (4n). After meiosis, each cell has a haploid set of chromosomes. 

n-->n happens in fungi, when haploid mycelia cells replicate but stay haploid. I'm a bit rusty, though, so I'm not too sure. 
n --> 2n is fertilization 
2n --> 2n is mitosis, the cell replication process for somatic cells.

Genetic engineering is the answer.