Answer:
The most effective advertising is very expensive and, therefore, wasteful.
Explanation:
In order for something to be considered economically wasteful it must use and dispose money carelessly.
Therefore options:
Do not apply since the options do not consider the costs of advertisement.
The only option that considers the cost of advertisement is: The most effective advertising is very expensive and, therefore, wasteful. It refers to the high costs of effective advertisement, and it implies that the money is not used carefully.