If a population of medium sized rodents is placed under a selective pressure that yields both very large and very small individuals it was most likely a. a stabilizing selection b. a disruptive selection c. a directional selection d. not a natural selection event *not d

Option b , disruptive selection

Explanation:

Let’s define all the terms given in the option –

a)Stabilizing selection – The average trait is expressed more commonly in a given set of population. For example if there are some dogs of black color and some are of white color , the population of dogs after sometime will have grey color dogs instead of having extreme black and white color dogs.  

b)Directional selection – Here the trait is expressed towards any one of the extreme limit. For example – Out of the black and white dogs,  the population of dogs after sometime will consists of either a black dogs or a white dogs.  

c)Disruptive selection – When only the extreme traits are expressed. For example – Out of the black and white dogs, the population of dogs after sometime will have only black dogs and white dogs and no  dog of any color in between black and white

Thus, option b is correct