听力原文：（Woman) Hello, Juan. This is Helen Luna at Magnum Heating Supplies. I've been goi

听力原文：(Woman) Hello, Juan. This is Helen Luna at Magnum Heating Supplies. I've been going over our customer records, and I see that you currently use our Model 200 filters for your heating systems. I'm just calling to ask. Have you considered upgrading to the Model 201 filters？

(Man) I guess it's a possibility, but the 200's seem to be doing the job just fine for us.

(Woman) Well, the reason I ask is that for the next 90 days the Model 201 filters will be on sale for the same price as the Model 200's you're using now, so this would be a good time to change to the newer model.

(Man) Hmm. Let me talk about it with our maintenance staff and see what they think.

What is the purpose of the woman's call？

A．She wants to upgrade her heating system.

B．She wants to find out a price.

C．She wants to sell a product.

D．She wants to have a filter repaired.