.........A.......( a type of cell ) in sporogenous mass undergo ........B...... ( a type of cell division ) to from a tetrad that on separation given rise to ........C ...... ( number ) functional microspores.
(a) `{:(A,B,C),("Pollen mother cell","Meiosis",4):}`
(b) `{:(A,B,C),("Pollen mother cell","Meiosis",1):}`
(c) `{:(A,B,C),("Megaspore mother cell","Meiosis",4):}`
(d) `{:(A,B,C),("Megaspore mother cell","Meiosis",1):}`

Options

A. `{:(A,B,C),("Pollen mother cell","Meiosis",4):}`
B. `{:(A,B,C),("Pollen mother cell","Meiosis",1):}`
C. `{:(A,B,C),("Megaspore mother cell","Meiosis",4):}`
D. `{:(A,B,C),("Megaspore mother cell","Meiosis",1):}`

Answer

To solve the question step by step, we need to fill in the blanks A, B, and C based on our understanding of the processes involved in microspore formation.

### Step 1: Identify the type of cell in the sporogenous mass
- The question mentions a type of cell in the sporogenous mass. In the context of pollen formation, this cell is known as the **pollen mother cell** (also referred to as microspore mother cell).

### Step 2: Identify the type of cell division
- The pollen mother cell undergoes a specific type of cell division to produce microspores. This process is called **meiosis**. Meiosis is a reduction division that results in the formation of haploid cells from a diploid cell.

### Step 3: Determine the number of functional microspores produced
- After meiosis, the pollen mother cell divides to form a tetrad of microspores. Each tetrad consists of four haploid microspores. Therefore, upon separation, the number of functional microspores produced is **4**.

### Final Answer
Thus, the correct answers for the blanks are:
- A: Pollen mother cell
- B: Meiosis
- C: 4

The correct option is **(a) {:(A,B,C),("Pollen mother cell","Meiosis",4):}**.