A phase-out of lead solder in cans began in the late 1970s.

• A. Early 1990s
• B. Late 1970s
• C. 1950s
• D. 2000s

Answer: (B)

The main idea is understanding when safety measures started shifting away from lead in food packaging. In the late 1970s, concerns about lead exposure from canned foods and growing regulatory emphasis pushed manufacturers to begin removing lead-containing solder from cans. This initiated the phase-out, with adoption continuing through the following years as safer, lead-free or alternative soldering methods became standard.

Choosing the early 1950s isn’t correct because awareness and regulation of lead in food packaging weren’t at the level they became later. A date in the 1990s or 2000s would reflect the continuation or completion of the shift, not its start, making the late 1970s the period when the phase-out began.