Final answer:
The question about deportations being halted on August 28 cannot be answered without additional context. The 'shell crisis' referred to a political crisis in Britain over shell production during World War I.
Step-by-step explanation:
The question regarding why deportations were halted on August 28 does not specify a year or context, thus the answer cannot be determined accurately without additional information. However, based on the information provided referencing the "shell crisis" in Britain, it appears the question is rooted in historical context. The correct answer to the provided reference question is: b) the political crisis over whether enough shells were being produced for the war effort. The shell crisis of Britain, which occurred during World War I, involved a shortage of artillery shells on the western front, leading to a momentous political crisis in 1915. This crisis exacerbated tensions between the military and civilian branches of government in the UK, ultimately resulting in the establishment of a coalition government and the Ministry of Munitions to better manage the war effort and munitions production.