Some experts regard as the most addictive drug available on the street, but other experts have questioned this assumption in recent years.

Some experts regard crack as the most addictive drug available on the street, but other experts have questioned this assumption in recent years.

Explanation:

The crack drug is just another type of cocaine which is available in the crystalline form (mostly powdered). This form of cocaine offers the ease of snorting and inhaling through smoking.

Despite of heavy monitoring and surveillance, this drug is illegitimately traded on the streets. Thus, it is easily available to those who ask for it. Experts debate over crack being the most addictive drug available on streets.

Because there has been a surge in the availability of other more addictive drugs that are available on the streets in the recent years.

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.  

the answer your looking for is c. : )