What method of working with an input/output device does this piece of code use?
LDR RO, EGPIO_P1_BASE
LDR R1, [RO, #PIN]
ORR R1, #Ox21
STR R1, [RO, #PIN]
a. Write-Modify-Read
b. Write 'all at once
c. Read-Modify-Read
d. Read-Modify-Write