Answer:
decreased.
Step-by-step explanation:
An increase in the time between when an order to trade a security is placed and when the order is executed most likely indicates that market efficiency has: decreased.
The fact about Market efficiency is that it does not require that the market price be equal to true value at every point in time. All it requires is that errors in the market price be unbiased, i.e., that prices can be greater than or less than true value, as long as these deviations are random.