Explanation:
A positive AND gate is a logic gate that produces a HIGH output only when all of its inputs are HIGH. It can be represented by the Boolean expression A.B.

On the other hand, a negative OR gate is a logic gate that produces a LOW output only when all of its inputs are LOW. It can be represented by the Boolean expression A+B.

Now, let's see how a positive AND gate is equivalent to a negative OR gate.

1. NAND gate is not the answer:
A NAND gate is a negative AND gate, which means it produces a LOW output when all of its inputs are HIGH. It can be represented by the Boolean expression A.B. Therefore, a NAND gate is not equivalent to a positive AND gate.

2. AND gate is not the answer:
An AND gate is a positive AND gate, which means it produces a HIGH output only when all of its inputs are HIGH. It can be represented by the Boolean expression A.B. Therefore, an AND gate is the same as a positive AND gate, not a negative OR gate.

3. NOR gate is not the answer:
A NOR gate is a negative OR gate, which means it produces a LOW output only when any of its inputs are HIGH. It can be represented by the Boolean expression A+B. Therefore, a NOR gate is not equivalent to a positive AND gate.

4. OR gate is the answer:
An OR gate is a positive OR gate, which means it produces a HIGH output when any of its inputs are HIGH. It can be represented by the Boolean expression A+B. By using De Morgan's law, we can write the Boolean expression for a negative OR gate as (A.B)'. This is the same as the Boolean expression for a positive AND gate. Therefore, an OR gate is equivalent to a positive AND gate.

Conclusion:
Hence, the correct answer is option B - OR gate.