Question

how can heritable variation increase fitness?
variations decrease the population size and make the population less desirable to predators.
the inherited variations create new adaptations that help an organism survive and pass them on.
heritable variations always lower fitness.

Explanation:

Heritable variations can lead to new traits. If these traits are beneficial (like better camouflage, more efficient foraging), they increase an organism's chances of survival. Organisms with such favorable heritable variations are more likely to reproduce and pass those traits (adaptations) to the next generation. This is in line with the principles of natural selection. The first option is incorrect as heritable variations don't necessarily decrease population size in a way that makes a population less desirable to predators (and even if they did, that's not the main way they increase fitness). The third option is wrong because heritable variations don't always lower fitness - sometimes they can be neutral or beneficial.

Answer:

The inherited variations create new adaptations that help an organism survive and pass them on.