What happens when a particle and its antiparticle collide? They combine nuclei
They break into quarks
They are converted to energy
They become antimatter

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.

your answer is c! hope this : )