When a skeletal muscle is at rest , which protein is bound to the actin filaments ? A. Voltage-gated channels
B. Other actin filaments
C. Troponin
D. Myosin

ok, but what is your question? as soon as you tell me i will answer your question : )

its c not d   tell me if that´s correct

answer: in 1900, there were no "workplace safety laws"!

explanation: at the beginning of this century, workers in the united states faced remarkably high health and safety risks on the job.

a century ago in 1900 about three hundred out of every one hundred thousand miners were killed on the job each year.

[industria] developments occurred within a legal and regulatory climate that diminished employer’s interest in safety. as a result, americans developed production methods that were both highly productive and often very dangerous.