So,
The sentence is: "Once she left the store, my mother realizes she forgot her purse on the counter."
The phrase "One she left the store" is in the past tense.
In the next phrase, "my mother realizes", the tense shifts to present.
In the final phrase, "she forgot her purse on the counter", the verb tense shifts back to the past tense.
Therefore, option A is correct.
The two opposing forces in WW1 were a) Allies and Central Powers.
The First World War started as a two-sided war between Austria-Hungary and Serbia in 1914. It evolved into a war in which thirty two countries took part. Britain, Russia, France, the United States and Italy formed The Allies. These countries battled against Austria-Hungary, Bulgaria, Ottoman Empire and Germany, known as the Central Powers.
I believe the answer is A. Hope that helps you
