In pea plants, red flowers and round pollen are known to be recessive traits. In a dihybrid cross experiment, lots of plants with red flowers and round pollen are found in the F2 generation. How is this possible?

The genes for flower color are linked to pea shape, but not pollen shape.
The genes for flower color and pollen shape are found on different chromosomes.
The genes for flower color and pollen shape are linked.
Multiple genes control the traits for flower color and pollen shape.