Which of the following tissues has dead cells ?
(a) Collenchyma
(b) Sclerenchyma
(c) Parenchyma
(d) Phloem

Options

A. Collenchyma
B. Sclerenchyma
C. Parenchyma
D. Phloem

Answer

To determine which of the following tissues has dead cells, let's analyze each option:

1. **Collenchyma (Option A)**:
- Collenchyma is a type of simple tissue that consists of living cells. It provides support to the plant while allowing for flexibility. Therefore, this option does not have dead cells.

2. **Sclerenchyma (Option B)**:
- Sclerenchyma is another type of simple tissue, but it is composed of dead cells. These cells have thickened secondary cell walls that are often lignified (hardened due to the presence of lignin). Sclerenchyma provides structural support and strength to the plant. Thus, this option has dead cells.

3. **Parenchyma (Option C)**:
- Parenchyma is also a simple tissue made up of living cells. It is involved in various functions such as storage, photosynthesis, and tissue repair. Therefore, this option does not have dead cells.

4. **Phloem (Option D)**:
- Phloem is a complex tissue that consists of various types of living cells, including sieve tubes and companion cells. It is responsible for the transport of nutrients and food throughout the plant. Thus, this option does not have dead cells.

Based on the analysis, the only tissue that contains dead cells is **Sclerenchyma (Option B)**.

### Final Answer:
**(b) Sclerenchyma**