**Explanation:**

In order to determine the number of members from scheduled castes in the assembly, we need to consider the information given in the question. Unfortunately, the question does not provide any specific data or context to work with. Therefore, it is not possible to accurately determine the number of members from scheduled castes in the assembly.

However, if we assume that there is a specific data or context given which we can use to determine the answer, we can proceed to solve the question based on that information.

Let's consider the options given:

a) 22
b) 20
c) 28
d) 30

Assuming that one of these options is the correct answer, let's evaluate each option to determine the possibility:

**Option a) 22:**
If there were 22 members from scheduled castes in the assembly, this could be a possible answer. However, without any additional information, we cannot confirm if this is the correct answer.

**Option b) 20:**
If there were 20 members from scheduled castes in the assembly, this could also be a possible answer. However, without any additional information, we cannot confirm if this is the correct answer.

**Option c) 28:**
If there were 28 members from scheduled castes in the assembly, this could be a possible answer. However, without any additional information, we cannot confirm if this is the correct answer.

**Option d) 30:**
If there were 30 members from scheduled castes in the assembly, this could also be a possible answer. However, without any additional information, we cannot confirm if this is the correct answer.

Based on the given options, we cannot definitively determine the correct answer without additional information or context from the question. Therefore, the correct answer cannot be determined.

It is important to note that providing relevant information and context in the question is crucial to accurately solve problems or answer questions. Without such information, it becomes difficult or impossible to determine the correct answer.