Table:
|  |  | Fiscal |
| --- | --- | --- |
|  | 2019 | 2018 |
|  |  | (in millions) |
| Acquisition-related charges: |  |  |
| Acquisition and integration costs | $  17 | $  8 |
| Charges associated with the amortization of acquisition-related fair value adjustments | — | 4 |
|  | 17 | 12 |
| Restructuring and other charges, net | 144 | 33 |
| Other items | 14 | — |
| Total | $  175 | $  45 |
Paragraphs:
Operating income in the Transportation Solutions segment decreased $352 million in fiscal 2019 as compared to fiscal 2018. The Transportation Solutions segment’s operating income included the following:
Excluding these items, operating income decreased in fiscal 2019 primarily as a result of lower volume, unfavorable product mix, and price erosion, partially offset by lower material costs.
Question:
Why did operating income decrease in fiscal 2019?
Answer: primarily as a result of lower volume, unfavorable product mix, and price erosion, partially offset by lower material costs.