Explanation:

Let's break down the sections and their doctrines:

- Doctrine of acceleration allows a prior interest to immediately vest in a person when an intermediate interest fails (e.g., dies before taking it). This is discussed under Section 27 of the Transfer of Property Act.

- Doctrine of conditional limitation refers to a condition where, on happening of a specified event, the interest is to end and pass on. This is governed by Section 28.

Now, let's review the options:

1. Sec. 27 and Sec. 28:

- Sec. 27: Acceleration

- Sec. 28: Conditional limitation

- Correct

2. Sec. 23 and Sec. 28:

- Sec. 23: Transfer contingent on happening of specified event

- Sec. 28: Conditional limitation

- Not correct for acceleration

3. Sec. 28 and Sec. 29:

- Sec. 29: Condition precedent

- Does not cover acceleration

4. Sec. 29 and Sec. 30:

- Sec. 30: Ulterior transfer

- Not specific to acceleration or conditional limitation

Therefore, the correct answer is Option 1: Sec. 27 and Sec. 28.