Final answer:
The correct order from smallest to largest population among the provided states is Washington, Virginia, Pennsylvania, Texas. Texas is known for being the second most populous state in the U.S., and population sizes generally reflect current trends and census data.
Step-by-step explanation:
The question is asking to list four U.S. states in order of their population sizes from smallest to largest. To determine the correct order, we can refer to the most recent population estimates available, acknowledging that populations can change and data may vary depending on the time of reference. Current population trends indicate that Washington and Virginia have smaller populations compared to Pennsylvania and Texas, with Texas being the second most populous state in the U.S. As such, option 'b' Washington, Virginia, Pennsylvania, Texas appears to be the correct order from smallest to largest population.