Last year, all the candidates who sought employment at ‘Clean n Green’ also applied for a position at ‘Mellow n Yellow’, and ‘Clean n Green’ and ‘Mellow n Yellow’ each offered suitable positions to half of these candidates. Therefore, each one of these candidates must have been offered a suitable position last year.

The argument above is based on which of the following assumptions about these candidates?

All the candidates were eminently qualified for a suitable position at either ‘Clean n Green’ or ‘Mellow n Yellow’.

All the candidates accepted a position offered at either ‘Clean n Green’ or ‘Mellow n Yellow’.

None of the candidates was offered a suitable position by both ‘Clean n Green’ and ‘Mellow n Yellow’ simultaneously.

None of the candidates had applied for suitable positions at places other than ‘Clean n Green’ and ‘Mellow n Yellow’.