The correct matching for the following pairs is
$$\,\,\,\,\,$$ List - $${\rm I}$$
(a) $$DMA$$ $$\,\,$$ $${\rm I}/O$$
(b) Cache
(c) Interrupt $${\rm I}/O$$
(d) Condition Code Register

$$\,\,\,\,\,$$ List - $${\rm II}$$
(1) High speed $$RAM$$
(2) Disk
(3) Printer
(4) $$ALU$$

When an interrupt occurs, an Operating System

The correct matching for the following pairs is

(a) Disk scheduling $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$(1) Round robin
(b) Batch processing $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ (2) $$SCAN$$
(c) Time sharing $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ (3) $$LIFO$$
(d) Interrupt processing $$\,\,\,\,\,\,\,\,\,\,\,$$(4) $$FIFO$$

An operating system contains 3 user processes each requiring 2 units of resource R.The minimum number of units of R such that no deadlocks will ever arise is