Answer:
Option D: NOW
Explanation:
In Microsoft Excel, NOW function can be used to return a serial number that  corresponds to the system date and time beginning with December 31, 1899. 
The NOW function is useful when a date and time is required for calculation or display. The value will be updated each time we open the Excel worksheet.  To use the NOW function, we can type in the formula as follows:
<em>=NOW() </em>
 
        
             
        
        
        
<span>Wireless networks usually use radio (b) signals to send data. </span>
        
                    
             
        
        
        
I believe it would be the anchor element.
<a href="#"></a>
Correct me if I'm wrong.
        
             
        
        
        
Answer:
Conditioned response 
Explanation:
In a famous experiment a dog drool at a sound that is made just before meals. This is considered a(n) conditioned response.
The dog has been conditioned to respond to the constant sound before his meal is served by drooling(salivating ) with the expectation of eating almost immediately after the sound had been made .