Monopolistically competitive and purely competitive industries are similar in that:

A) both are assured of short-run economic profits.
B) both produce differentiated products.
C) the demand curves facing individual firms are perfectly elastic in both industries.
D) there are few,if any,barriers to entry.

Both monopolistically competitive and purely competitive industries have few, if any, barriers to entry. In purely competitive industries, there are many small firms producing homogeneous products, while in monopolistically competitive industries, there are many small firms producing differentiated products. However, the demand curve facing an individual firm in a purely competitive industry is perfectly elastic, while in a monopolistically competitive industry it is downward sloping, reflecting the product differentiation. Both industries may also earn zero economic profits in the long run due to the ease of entry and exit of firms.