The extent and depth of the analysis of potential suppliers is dependent on: the number of available suppliers. the expertise of the purchaser. the cost and importance of the item. the lead time available. all of the above.

The answer is: All of the above

Explanation:

Many factors influence the process of picking your best possible supplier.

Some of them are the number of potential suppliers. For example, if you need to buy chemical products in large quantities, you will probably analyze two or three possible options. But if you are looking for a cleaning company then you might have dozens of different options. The most expensive and important your supply, the deeper the vendor analyzes should be. If you work at a construction company that specializes on bridges, then you will need to thoroughly analyze your steel suppliers.  How fast you need your supplies is also something that will determine how much you can analyze your vendors. If a fire breaks out at an oilfield, the oil company will hire the best firefighters they can without considering their cost (and they are extremely expensive). Of course the expertise of the supplier is important, like any job if the employee knows what his doing he will do it faster and better. Rookies will always take more time to do any type of work.  

What do you mean by that?