Identify the Letter of the Choice That Best Matches the Phrase

Identify the letter of the choice that best matches the phrase or definition.
-A proprietary mobile operating system

A) virtualization
B) mobile operating system
C) Blackberry
D) sleep mode
E) hibernate
F) administrator account
G) user name
H) password
I) Google Play
J) permissions
K) thrashing
L) NFC
M) Passbook
N) command language
O) Wallet
P) SkyDrive
Q) Linux
R) antivirus
S) iCloud
T) account