Which sentence correctly distinguishes advice from obligation?
กYou must save a copy, but you might encrypt confidential files by policy.
ขYou should to save a copy and must to encrypt files.
คYou can saving a copy but must encrypted files.
งYou should save a copy, but you must encrypt confidential files.
เฉลยอธิบาย
should เป็นคำแนะนำ ส่วน must เป็นข้อบังคับ