If a monopolistic competitor raises its price, it customers than a perfectly competitive firm, but customers compared to the number that a monopoly that raised its prices would.

It would lose less customers than perfectly competitive firm, but more customers compared to a monopoly that raised its price would

Explanation:

Perfect Competition is a market form with many buyers & sellers, selling homogeneous products at constant prices Monopolistically competitive firm has many sellers, selling slightly differentiated products, at different prices. Monopoly is a market structure having single seller of a product in the market.

So, these market forms have following control over prices/ elasticity of demand :

Perfect competition has uniform prices, perfectly elastic horizontal demand curve. Firm is just a price taker, has no control in price. Monopolistic competition firm has different prices because of differentiated products. But has only certain control on price, demand is elastic due to substitutes competition Monopoly, being single seller has full control over price, is 'price maker'. Lack of substitutes also make its demand inelastic.

Therefore : A price rise would - reduce perfect competition firm demand the most;  more than that & less than monopoly for monopolistic competitive firm demand ; the least for monopoly demand