B.) The rumble of thunder.
I hope this helps. :p
        
                    
             
        
        
        
Answer:
CPU.
Explanation:
A processor, also known as a Central Processing Unit, is a piece of hardware in a computer that performs basic operations and control when executing program code. 
Processors are usually made as integrated circuits closed in a hermetic casing, often with gold-plated leads (used for resistance to oxidation) and in this form they are called microprocessors - in common speech the terms processor and microprocessor are used interchangeably. The heart of the processor is a single crystal of silicon, on which a series of semiconductor layers have been applied by means of photolithography, forming, depending on the application, a network of several thousand to several billion transistors. Its circuits are made of metals with good electrical conductivity, such as aluminum and copper.
 
        
             
        
        
        
If you want to set the sticky bit on an existing directory, subdir, without otherwise altering its permissions. to do so, you should type chmod a <u>t  <subdir>.</u>
<h3>What is 
Subdir?</h3>
The Definition of the term subdirectory is known to be a kind of an organizational directory that can be seen on a computer.
It is known to be one that can be found inside another directory  such as a subfolder. It is seen as the file a person is looking for and it is one that needs to have an extension.
Therefore, if you want to set the sticky bit on an existing directory, subdir, without otherwise altering its permissions. to do so, you should type chmod a <u>t  <subdir>.</u>
Learn more about directory from
brainly.com/question/14845522
#SPJ1 
See full question below
You want to set the sticky bit on an existing directory, subdir, without otherwise altering its permissions. To do so, you should type:
chmod a+_____ <subdir>
- s
- p
- b
- t