Answer:On the Home tab, in the Views group, click View, and then click Design View. In the table design grid, select the field or fields that you want to use as the primary key. To select one field, click the row selector for the field that you want.
Explanation:
I believe it’s C.) data link layer
No because its created for ios
Answer:
To make sure that data sent from a device is just received by appropriate device we use "<u>Switch</u>"
Explanation:
Switch is the networking device. It is used to connect all the Local area networks in a computer network. The switch store the addresses of all computers over the network. Whenever data packet arrives to the switch, it just read the address of destination computer and just send it to appropriate device instead of all devices.
Hub is also used for this purpose, but it has no ability to read the address and send the packet to all devices over the network.
<em>So, we use Switch to send data to appropriate device.</em>
B) A system that locates information on the World Wide Web