Henry Gantt developed the concept of Bar Charts (later called Gantt Charts) for planning and scheduling of construction and industrial projects—identify the correct year from the options.

Introduction / Context:
Gantt Charts are a foundational visual tool in construction and project management for planning, scheduling, tracking progress, and coordinating resources. This question checks historical awareness of when Henry L. Gantt's bar-chart method emerged, situating the technique within the evolution of management science.

Given Data / Assumptions:

• We are asked to choose a year from the options that best matches the emergence of Gantt's bar-chart idea.
• Options: 1880, 1900, 1920, 1940, 1950.
• Focus is on the earliest period when Gantt's bar charts became known in practice.

Concept / Approach:
Gantt popularized bar charts during the early 20th century to display task durations and overlaps over calendar time. Although refinements continued through the 1910s, the correct choice among the given options corresponds to the period around the turn of the century when the concept took shape and began influencing practice.

Step-by-Step Solution:
Step 1: Recognize that Gantt's contributions belong to the early 1900s.Step 2: Compare the plausible early date (1900) with later dates (1920, 1940, 1950).Step 3: 1920 is after Gantt's lifetime—he died in 1919; later dates are too late for first development.Step 4: 1880 predates Gantt's professional period of influence.Step 5: Therefore select 1900 from the given options.

Verification / Alternative check:
Historical management literature places Gantt's bar-chart usage in the early 1900s, with widespread adoption during World War I. Among the offered choices, 1900 is the best representative year.

Why Other Options Are Wrong:

• 1880: Too early relative to Gantt's career and the emergence of scientific management.
• 1920: After Gantt's death; charts were already established by then.
• 1940: Long after initial development; era of broader project management advances.
• 1950: Far too late for first appearance.

Common Pitfalls:
Confusing first development with later popularization; assuming mid-century dates due to modern usage; mixing up Gantt with later network methods (PERT/CPM).

Final Answer:
1900