Sentence improvement — Choose the correct preposition after ‘‘heading’’ in ‘‘It became clear that the strangers were heading into a serious disaster.’’ for accurate direction and idiomatic usage.

Given sentence
It became clear that the strangers were heading into a serious disaster.

Concept/Approach
With verbs of motion such as ‘‘head’’, the preposition ‘‘towards’’ expresses movement in the direction of a state or event. ‘‘Into’’ often implies literal entry into a physical space; here the figurative direction is better captured by ‘‘towards’’.

Option analysis
A: along — Means ‘‘following the length of’’; wrong sense.B: towards — Best idiomatic fit: ‘‘heading towards a disaster’’.C: for — ‘‘Heading for’’ can work in casual style, but the most precise in formal usage is ‘‘towards’’ a disaster.D: No improvement — ‘‘into a disaster’’ sounds awkward and overly literal.

Common pitfalls
Confusing physical entry (‘‘into the room’’) with directional tendency (‘‘towards disaster’’).

Final Answer
towards