The correct answer is B. SIMM.
A SIMM (Single In-line Memory Module) is a type of memory module that has 30 pins on each side. It is a single-sided module, meaning that the memory chips are only on one side of the module. SIMMs were used in early personal computers, but they have been replaced by DIMMs (Dual In-line Memory Modules) in most modern computers.
A DIMM is a type of memory module that has 72 pins on each side. It is a double-sided module, meaning that the memory chips are on both sides of the module. DIMMs are more common than SIMMs because they can hold more memory and they are faster.
SDRAM (Synchronous Dynamic Random-Access Memory) is a type of memory that is synchronized with the system clock. This means that it can access data faster than asynchronous memory. SDRAM is the most common type of memory used in modern computers.
A. DIMM is incorrect because SIMMs have 30 pins, while DIMMs have 72 pins.
B. SIMM is correct because the question states that the memory slots have 30 pins.
C. SDRAM is incorrect because the question does not ask about the type of memory, but about the type of memory module.
D. All of the above is incorrect because only one of the options is correct.
E. None of the above is incorrect because one of the options is correct.