Which of the following is correct statement

Options

A. In blastulation major presumptive and organ forming areas are segregated into definite points of the blastoderm
B. Blastulation establishes the three germinal layers
C. Blastulation of frog is known as discoblastula
D. Fluid filled space in blastula is known as archenteron

Explanation

To determine the correct statement regarding the process of blastulation, let's analyze the options step by step.

### Step-by-Step Solution:

1. **Understanding Blastulation**:
- Blastulation is the process that leads to the formation of the blastula from the zygote. It involves cell division and differentiation.

2. **Formation of the Blastula**:
- The zygote undergoes several rounds of cell division (cleavage), resulting in a multicellular structure. Initially, it forms a solid ball of cells (morula) and then transforms into a hollow structure called the blastula.

3. **Identification of Correct Statement**:
- **Option 1** states that during blastulation, major presumptive and organ-forming areas are segregated into definite points of the blastoderm. This is a correct statement as the blastoderm is where the differentiation of cells occurs, leading to the formation of various organs.

4. **Analyzing Other Options**:
- **Option 2** claims that blastulation establishes three germinal layers. This is incorrect; the establishment of three germinal layers (ectoderm, mesoderm, and endoderm) occurs during gastrulation, not blastulation.
- **Option 3** states that the blastulation of frogs is known as disco-blastula. This is incorrect; the correct term for frog blastula is "silo-blastula."
- **Option 4** mentions that the fluid-filled space in the blastula is known as arcanturon. This is also incorrect; the fluid-filled space is called the "blastocoel."

5. **Conclusion**:
- Based on the analysis, the correct statement is **Option 1**: "In blastulation, major presumptive and organ-forming areas are segregated into definite points of the blastoderm."