As the number of firms in a monopolistically competitive industry increases, average cost and prices . A rises; rise B rises; fall C falls; rise D falls; fall

B rises; fall

Explanation:

In a monopolistic competition involves a group of firms in an industry that sell goods that are similar but not identical, there are large number of small firms, relative mobility of resources, and extensive knowledge.

As firms in a monoploistic competition increases, the number of similar goods increase. There is more need for advertising and other promotional activities in order to maintain competive edge. So average cost rises.

Price also falls because the number of firms selling similar products has increased, so a firm cannot keep increasing price because people will go for other similar products.

the correct answer would be b, when, queen, calder hall and london.

explanation:

we always capitalize words when a paragraph or sentence is starting, when an important name is used, when a place is being written, or simply when a noun is used, etc. so in this sentence, sentence is starting from 'when', so it will be written in capital letters. secondly, queen is considered to be an important person, so it will also be written in capital letter. next, the name of the town is mentioned, i-e calder hall, which will also be written in capital letters. in the last,   city name is being used, 'london', which will also be written in capital letters. so option b is the most appropriate one.