Which of the following types of memory is used with laptops?

RAMBUS (RDRAM) was a proprietary high-speed memory type used in some desktops and workstations, not a laptop-specific form factor.

SODIMM (Small Outline Dual Inline Memory Module) is the standard memory form factor designed specifically for laptops. Its compact size - roughly half the length of a full DIMM - allows it to fit into the tight confines of a laptop motherboard, making it the default choice for portable computing.

ECC (Error-Correcting Code) describes a memory feature for data integrity used in servers and workstations, not a form factor exclusive to laptops.

SDRAM is a memory technology generation (Synchronous DRAM) that exists in both desktop DIMM and laptop SODIMM form factors, so it does not specifically identify laptop memory.