Decision support systems:
a. are used for operational, tactical, and strategic decision making.
b. are used only when making structured decisions.
c. provide reports with fixed and standard formats.
d. require user requests for reports developed by systems personnel.

Decision support systems are used for operational, tactical, and strategic decision making.  

Explanation:

A type of computer programme which is used for judgement, determination, course of action in any type of organization and also in business is known as decision support system.

It works with sift of huge massive data, compelling the comprehensive information which can be used for solving the problem and help to take decision. It presents target, revenue of project and also sales figure.

this statement is true.

forests are public goods, available for everybody. when usage of such a good becomes interesting for consumers and its usage increases, there can be a risk of overexploitation. it is a non rival good therefore, if one person consumes the good it does not reduce the availability for subsequent consumers.

these caracteristics require the establishment of measures in order to prevent the destruction of a commonly owned space, for example, to restrict the amount of people that have access to the same time.

d - failures.

the only attempted british colony in north america before 1600 was roanoke, virginia, which was a total failure. england claimed several areas, including newfoundland, but made no sustainable attempts to colonize them before 1600.