To find the correct answer, we need to follow the given conditions:
1. The number is a multiple of 23.
2. The number is an odd number.
3. The number has 3 digits.
4. The number is a multiple of 7.

Let's analyze each option to see which one satisfies all the conditions:

a) 161
b) 207
c) 205
d) 159

Option a) 161:
- This number is a multiple of 23 because 23 * 7 = 161.
- This number is an odd number because the last digit is 1.
- This number has 3 digits.
- This number is a multiple of 7 because 7 * 23 = 161.

Option b) 207:
- This number is not a multiple of 23 because 207 / 23 = 9 with a remainder of 6.
- This number is an odd number because the last digit is 7.
- This number has 3 digits.
- This number is not a multiple of 7 because 207 / 7 = 29 with a remainder of 4.

Option c) 205:
- This number is not a multiple of 23 because 205 / 23 = 8 with a remainder of 21.
- This number is an odd number because the last digit is 5.
- This number has 3 digits.
- This number is not a multiple of 7 because 205 / 7 = 29 with a remainder of 2.

Option d) 159:
- This number is not a multiple of 23 because 159 / 23 = 6 with a remainder of 21.
- This number is an odd number because the last digit is 9.
- This number has 3 digits.
- This number is not a multiple of 7 because 159 / 7 = 22 with a remainder of 5.

Therefore, the correct answer is option a) 161, as it satisfies all the given conditions.