Depending upon size and centromere position, the 46 chromosomes in humans have been divided into how many groups?

The correct option is C 7
Human chromosomes are divided into 7 groups A, B, C, D, E, F and G depending upon their size and position of centromere. Group A chromosomes are chromosomes 1 to 3. These are largest chromosomes and are metacentric, centromere is in the center. Group B chromosomes include chromosomes 4 and 5. These are large and are submetacentric. Group C chromosomes include chromosomes 6 to 12 and X. These are medium in size and are submetacentric. Group D chromosomes include chromosomes 13 to 15. These are medium in size and are acrocentric, centromere is towards the one end of chromosome. Group E chromosomes include chromosomes 16 to 18. These are medium in size and are metacentric and submetacentric. Group F chromosomes include chromosomes 19 and 20. These are small in size and are metacentric. Group G chromosomes include chromosomes 21, 22 and Y. These are small in size and are acrocentric.

Thus, the correct answer is option C.