nAnswer:
A.
Explanation:
The compression couplings can be defined as a set of screw, compression, and indenter. A compression fitting is a type of coupling used to connect pipes. A compression couplings is used to connect fixtures and tubings.
It contains screw, compression, and indenter. Therefore, option A is correct answer.
R₂ and R₃ can be replaced by:

The total R of the circuit is R₁+R₅+R₄ = 706 2/3
So the current in the circuit I=V/R is 100/(706 2/3) = 15/106 A
(I'm deliberately not trying to round the result)
The voltage drop over R₄ is V=I*R = 15/106 * 500 ≈ 70
So answer C would be my choice.
DES is a commonly used symmetric encryption
A) is a commonly used symmetric encryption
<u>Explanation:</u>
DES stands for Data Encryption Standard. It is a symmetric key algorithm and is used for encrypting electronic data. It was developed in 1975. DES is one of the oldest encryption standards to be used in the industry.
The algorithm takes 16 rounds of permutations in order to encrypt data. But now, with the advent of technology, as new algorithms have been designed and put in use, DES is less preferable.
In the process of key generation, some keys generated sometimes turn out to be weak and hence are prone to attacks. If not for the weak keys generation, DES works perfectly fine and is an effective algorithm to encrypt data.