Final answer:
To lose 75% of its radioactivity, tritium will take 24.52 years.
Step-by-step explanation:
To find the amount of time necessary for tritium to lose 75% of its radioactivity, we can use the concept of half-life. The half-life of tritium is given as 12.26 years. In each half-life, the amount of tritium will decrease by half. Therefore, to lose 75% of its radioactivity, it will take 2 half-lives.
So, the total amount of time necessary would be 2 * 12.26 years = 24.52 years. Therefore, the correct answer would be B) 24.52 years.