Option 1 -> Forms "...at significant risk to protect..." which creates an illogical connection between risk and protection.
Option 2 -> Starts with "expansion" without context, making it grammatically incomplete and unclear.
Option 3 -> Creates a logical flow: cyber threats increased → data at risk → requires security measures → to protect people/organizations.
Option 4 -> Begins with "to protect" (infinitive clause) without establishing what needs protection first.
Hence, Option 3: (B), (A), (D), (C) -> The sentence reads: "Cyber threats have increased due to digital expansion, putting sensitive data at significant risk, requiring stronger security measures and protocols to protect individuals and organizations worldwide" - this follows a clear cause-effect-solution structure -> correct