You are in the process of reviewing bids from various vendors for work on your project. One of the bidding vendors has the history of delivering on time and within budget, and you have previously worked with this company successfully on previous engagements. You receive a call from the manager submitting the bid enquiring about how the process is going. He asks to have lunch with you to discuss the bid. What is the BEST response?

a) Do not mention the other bidders but simply inform him that based on his past experience , he has a good chance of winning the business
b) Inform him that it would be inappropriate to discuss the matter at all and document the communication
c) Inform him that it would not be appropriate to discuss the matter over phone during business hours, but that an informal, lunch discussion would be more appropriate.
d) Politely avoid continuing the conversation and disregard the bid