What is the correct sequence of the following step in the fabrication of a monolithic, Bipolar junction transistor? 1. Emitter diffusion2. Base diffusion3. Buried layer formation4. E pi-layer formation Select the correct answer using the codes given below:

• A. 3, 4, 1, 2
• B. 4, 3, 1, 2
• C. 3, 4, 2, 1
• D. 4, 3, 2, 1