Which of the following statements with regards to random file organization is correct?

a. In order to avoid overflow, the hashing algorithm that distributes keys to bucket addresses needs to be carefully chosen.

b. A higher loading factor leads to less overflow but also more wasted storage space.

c. Retrieving a record only requires a single block access, more particularly a random block access to the first block of the bucket indicated by the hashing algorithm.

d. Division, a hashing technique that divides the key by a positive integer M and takes the remainder as the record address, frequently performs very poorly.