Your answer is -
B. Folder Is the best place to save it 
        
                    
             
        
        
        
Answer:
"Waterfall" is the correct answer for the above question.
Explanation:
- The Waterfall model is a model which is the first model recognized by some scientists is used to states some rules to develop the software. It is based on the phases of the SDLC. The SDLC is the collection of phase that is used in software development.
- The waterfall model moves like water moves. It means any next phase starts if the previous phase is completed and the user can not move into previous steps of the model.
- This is also asked by the question. Hence the answer is the waterfall model.
 
        
             
        
        
        
Answer:
<u>720</u> possible PIN can be generated.
Explanation:
To calculate different number of orders of digits to create password and PIN, we calculate permutation. 
Permutation is a term that means the number of methods or ways in which different numbers, alphabets, characters and objects can arranged or organized. To calculate the permutation following formula will be used:
nPr = n!/(n-r)!
there P is permutation, n is number of digits that need to be organize, r is the size of subset (Number of digits a password contains)
So in question we need to calculate 
P=?
where 
n= 10   (0-9 means total 10 digits)
r= 3     (PIN Consist of three digits)
So by using formula
10P3 = 10!/(10-3)!
         =10!/7!
         = 10x9x8x7!/7!
         = 10x9x8
         = 720
 
        
             
        
        
        
Answer: Proxy server
Explanation: Proxy server is a type of server that is acts as interface between the network on huge scale and any local network. This server provides the feature of security, operations, privacy etc in the network system. They also help in improving the performance of the network.
It can work as the web filter to eliminate the unwanted websites.They acts as the gateway by  observing the website that is being browsed by the other user.Thus installation of proxy server should implemented on the organization.